The contextual model proposed for the Duke EC predicts that psychosocial factors may influence physiological mechanisms that may increase risk for the development of hypertension in older blacks. The purpose of this study is to test specific hypotheses concerning the relationship between psychosocial factors and physiological functioning. Specifically, this study will determine whether chronic stress is associated with increased sympathetic nervous system (SNS) activity, enhanced sodium retention, and augmented vascular reactivity -- all of which might increase risk for hypertension. Furthermore, this research will determine if the effects of stress may be moderated by social support and religious participation. The following hypotheses will be tested: (1) Individuals high in self-report of stress will exhibit higher levels of SNS hormones, greater sodium retention, and greater vascular reactivity compared to individuals reporting lower levels of stress. (2) Social support and religious participation will be associated with decreased SNS hormonal levels, decreased retention, and lower levels of vascular reactivity. (3) Perceived stress will interact with social support and with religious participation such that the effects of high levels of stress will be moderated by high levels of social support or religious participation. We will also examine on a preliminary basis the effects of anger, hostility, and "John Henryism" on potentially hypertensinogenic physiological phenomena. The proposed studies are perhaps the first to examine the association between specific sociocultural factors and physiological processes suspected to be involved in the development of hypertension in older blacks.